[hpsdr] PC SM PSUs

Chris Smith chris at vspl.co.uk
Fri Sep 24 03:36:45 PDT 2010


Hi

I vaguely remember discussion on this reflector, in the early days of HPSDR, regarding low noise PSUs for the PC driving PowerSDR. 

What I can't remember is the consensus regarding such PSUs.

I'm asking because I can see regular and powerful spurs all across the 80m band. These look like an AM carrier modulated by a single tone. I.e. there is a central large peak (the carrier) with two smaller equal amplitude peaks equally spaced either side of the carrier (the sidebands). 

I can only assume that these are caused by either hash from the SM PSU or clock signals radiating from the motherboard. I feel that the latter case is less likely as the major clocks are in the 10s or 100s of MHz not down at 3.5 MHz.

I'm aware that cheap PC style SM PSUs tend not to have filtering on the mains input despite there being provision for such in the PCB etch. Often the filter components are missing and jumpers fitted instead.

So, can anyone recommend a PSU for my desk-top PC which has proper mains filtering and which won't hit me too hard where it hurts - my wallet!? I'm saving hard for Alex. :-)

BTW I'm using an Intel Atom m/board as the prime mover.

Cheers & 73

de Chris G4NUX
 1285324605.0


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